Between 2007-2012, America’s most politically active corporations spent $5.8 billion on federal lobbying and campaign contributions. A Sunlight Foundation analysis suggests, however, that what they gave pales compared to what they got: $4.4 trillion in federal benefits.

The potential for an upset of veteran Sen. Pat Roberts is drawing millions in late contributions to Kansas, some of the more than $300 million outside spenders are investing to influence the outcome of Tuesday's races.

Voters in states with competitive races are being overloaded with advertising from outside interests trying to influence their vote. In red-hot Alaska, outsiders have spent at least $120 for each likely voter.